PASSIVE WEAR-INDICATING SENSOR FOR IMPLANTABLE PROSTHETIC DEVICE

• US 20070088442A1
• Filed: 10/16/2006
• Published: 04/19/2007
• Est. Priority Date: 10/14/2005
• Status: Abandoned Application

• Current Assignee: MicroCHIPS Inc.
• Original Assignee: MicroCHIPS Inc.
• Inventors: Prescott, James, Santini, John, Cima, Michael, Staples, Mark, Coppeta, Jonathan, Shelton, Kurt
• Application Number:
  US11/549,831
• Publication Number:
  US 20070088442A1
• Time in Patent Office: Days
• US Class Current: 623/18.110
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/4514 Cartilage
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 6/037 Emission tomography
• CPC Class Codes: A61B 6/481 involving the use of contrast agents
• CPC Class Codes: A61B 8/481 involving the use of contrast agent, e.g. microbubbles introduced into the bloodstream analysis of echo signal exploiting properties of a contrast enhancer in devices for short-range imaging with acoustic waves G01S7/52039
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/3804 for elbows
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/40 for shoulders
• CPC Class Codes: A61F 2/4425 made of articulated components
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2/488 Means for detecting or monitoring wear
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30004 the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30075 : swellable, e.g. when wetted
• CPC Class Codes: A61F 2002/30113 : circular
• CPC Class Codes: A61F 2002/30154 : square
• CPC Class Codes: A61F 2002/30156 : triangular
• CPC Class Codes: A61F 2002/30326 : differing in height or in length
• CPC Class Codes: A61F 2002/30673 : Lubricating means, e.g. synovial pocket
• CPC Class Codes: A61F 2002/30677 : Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30682 : Means for preventing migration of particles released by the joint, e.g. wear debris or cement particles
• CPC Class Codes: A61F 2002/30733 : Inserts placed into an endoprosthetic cavity, e.g. for modifying a material property
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/3081 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30838 : Microstructures
• CPC Class Codes: A61F 2002/30878 : with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
• CPC Class Codes: A61F 2002/30884 : Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/30971 : Laminates, i.e. layered products
• CPC Class Codes: A61F 2002/3401 : with radial apertures, e.g. radial bores for receiving fixation screws
• CPC Class Codes: A61F 2002/3456 : ellipsoidal or having a flattened polar region
• CPC Class Codes: A61F 2002/3469 : with non-radial inner bores or canals
• CPC Class Codes: A61F 2002/3495 : Spherical shell significantly smaller than a hemisphere, e.g. extending over less than 160 degrees
• CPC Class Codes: A61F 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2002/4662 : for measuring penetration depth
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2210/0061 : swellable
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0023 : triangular
• CPC Class Codes: A61F 2250/0014 : having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
• CPC Class Codes: A61F 2250/0037 : differing in height or in length
• CPC Class Codes: A61F 2310/00011 : Metals or alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61L 27/50 : Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials

Abstract

A method is provided for non-invasively detecting mechanical wear of a prosthetic device implanted in a patient, the method comprises using a non-invasive imaging technique to image the prosthetic device that includes a wear indicating composition; and detecting whether the wear indicating composition has been released from the prosthetic device, and, if so, the location, type, and/or amount thereof. The implant device includes a prosthetic device body having at least one outer surface area; at least one reservoir (e.g., a plurality of discretely spaced micro-reservoirs) in the device body; a wear indicator composition disposed in said at least one reservoir, wherein mechanical wear of the at least one outer surface area of the device body in vivo causes release of at least part of the wear indicator composition. The prosthetic device body may be one for replacement of a hip, a knee, a shoulder, an elbow, or a vertebra.

Claims

1. A medical implant device having a mechanical wear detector comprising:

a prosthetic device body having at least one outer surface area;

at least one reservoir in the device body;

a wear indicator composition disposed in said at least one reservoir,

wherein mechanical wear of the at least one outer surface area of the device body in vivo causes release of at least part of the wear indicator composition.

2. The device of claim 1, wherein the prosthetic device body is a bone prosthesis or part thereof.

3. The device of claim 2, wherein the bone prosthesis is adapted for replacement of a hip, a knee, a shoulder, an elbow, or a vertebra.

4. The device of claim 1, wherein the device body and surface area in which the reservoirs are defined comprises a biocompatible material selected from metals, polymers, ceramics, and combinations thereof.

5. The device of claim 1, wherein the surface area comprises a polyethylene.

6. The device of claim 1, wherein the wear indicator composition comprises one or more matrix materials.

7. The device of claim 6, wherein the one or more matrix materials comprises a biodegradable, water-soluble, or water-swellable matrix material.

8. The device of claim 7, further a therapeutic or prophylactic agent in the matrix material degrades or dissolves in vivo to controllably release the therapeutic or prophylactic agent.

9. The device of claim 1, wherein the wear indicator composition is provided in two or more layers.

10. The device of claim 1, comprising a plurality of discretely spaced reservoirs.

11. The device of claim 10, wherein the reservoirs are micro-reservoirs.

12. The device of claim 10, wherein the reservoirs are formed in the device body by a microfabrication method.

13. An orthopedic implant device for controlled local release of a beneficial substance in vivo comprising:

a device body which comprises a release system which includes at least one beneficial substance,

wherein the beneficial substance is releasable from the device in vivo upon mechanical wear of at least one surface of the device body.

14. The device of claim 13, wherein the amount of beneficial substance released is proportional to the amount of mechanical wear experienced by the device body.

15. The implant device of claim 13, wherein the beneficial substance comprises a therapeutic or prophylactic agent.

16. The implant device of claim 15, wherein the therapeutic or prophylactic agent is a bisphosphonate.

17. The implant device of claim 13, wherein the beneficial substance comprises a biocompatible lubricating agent.

18. The implant device of claim 13, wherein the at least one beneficial substance is disposed in a plurality of discrete reservoirs located in the device body.

19. The implant device of claim 16, wherein the bisphosphonate is dispersed in a non-porous polymeric material which forms a wear surface on the device.

20. The implant device of claim 13, which is part of a knee implant, a hip implant, a bone resurfacing device, or an artificial vertebra.

21. The implant device of claim 13, further comprising:

at least one reservoir in the device body;

a wear indicator composition disposed in said at least one reservoir,

wherein mechanical wear of the at least one outer surface area of the device body in vivo causes release of at least part of the wear indicator composition.

22. A non-invasive method for detecting mechanical wear of a prosthetic device implanted in a human or other animal, the method comprising:

using a non-invasive imaging technique to image the prosthetic device which includes a wear indicating composition; and

detecting wear indicating composition that has been released from the prosthetic device.

23. The method of claim 22, wherein the imaging technique comprises magnetic resonance imaging, x-ray, ultrasound, positron emission tomography, or fluoroscopy.

24. The method of claim 22, wherein release of the wear indicating composition is detected by identifying the presence of at least a portion of the wear indicating composition at one or more positions remote from its original position in the prosthetic device.

25. The method of claim 22, wherein release of the wear indicating composition is detected by identifying the absence of at least a portion of the wear indicating composition from its original position in the prosthetic device.

26. The method of claim 22, wherein the prosthetic device includes wear indicating composition which is provided in each of a plurality of discrete reservoirs in the device.

27. The method of claim 26, wherein the reservoirs are microreservoirs.

28. The method of claim 22, which further comprises, before the step of using a non-invasive imaging technique, administering to the human or other animal a substance that interacts or binds with the wear indicating composition to enhance the detection of wear indicating composition that has been released from the prosthetic device.

29. The method of claim 28, wherein the non-invasive imaging technique comprises positron emission tomography and the substance comprises a radioactive agent.

30. A mechanical apparatus comprising:

a first structure having a wearable surface, which wears upon frictional engagement with a second structure during operation of the apparatus;

a plurality of discrete microreservoirs disposed in defined locations in the wearable surface; and

at least one wear indicating composition contained in the microreservoirs,

wherein upon a predetermined amount of wear of the wearable surface at least a portion of the at least one wear indicating composition is released from one or more of the microreservoirs.